The number 6 has a special significance. It represents the Law and Order and also associated with a Karmic Law of cause and effect. Number 6 is a perfect number, symmetrical in all parts, the number of the Soul.
Plums are ready they are not hard as a rock, soft just a little when pressed. I wouldn't use windfall, they are too ripe. If your making jam, it is best to use some underripe with the ripe ones. Last season I added small diced candied ginger to the plum jam. Really turned out nice.
Once ripe, plums will keep at room temperature for around three or four days. Or store them in the fridge in a perforated bag for up to five days. Eat sweet dessert plums raw. Halve and roast (15-20 minutes); poach whole (15-25 minutes); stew (10 minutes).